The present invention relates to a crane which is installed on the rooftop of the building or the like and which is capable of effectively pulling up an object from a narrow road onto a narrow rooftop and setting it up on a rooftop.
The present applicant has previously proposed a solar ray collecting device in which solar rays are focused by a lens or the like and guided into an optical conductor and transmitted through an optical conductor to an optional desired place for use in illumination, etc. The afore-mentioned solar ray collecting device is often installed and used on the rooftop of a building. However, elevator towers, water-supply tanks, etc., are often built on the rooftops of buildings. Some of them have very little space left. Furthermore, in a big city (especially, a megalopolis), many roads are narrow, and therefore it may be very difficult to install such a solar ray collecting device a described above in a predetermined place on the rooftops of buildings.